there’s this tendency of big aerospace companies to outsource everything. That’s been trendy in lots of industries, but aerospace has done it to a ridiculous degree. They outsource to subcontractors, and then the subcontractors outsource to sub-subcontractors, and so on. You have to go four or five layers down to find somebody actually doing something useful—actually cutting metal, shaping atoms. Every level above that tacks on profit—it’s overhead to the fifth power.

Not cheap, but i think the cheapest solution is to use a dedicated nuclear transmartian shuttle, with a decreasing total cost as the number of missions increase.Its only job is to acclerate from Low earth orbit to martian orbit and back, with the additional option to use the martian atmosphere for aerobraking, at least for a partial orbital capture.

Initially it makes the first mission more expensive than an Appolo style mission, but as the number of missions increase, each time it saves a Heavy Lifter.

Since you quote Zubrin in wikipedia:"...Once there, a series of chemical reactions (the Sabatier reaction coupled with electrolysis) would be used to combine a small amount of hydrogen (8 tons) carried by the Earth Return Vehicle with the carbon dioxide of the Martian atmosphere to create up to 112 tonnes of methane and oxygen..."

Now we know that MArs has plenty of underground ice, so is it really necessary to bring 8 tons of hydrogen when it can be obtained by electrolysis from Martian ice?(along with the Oxygen by the way). And CO2 is the main atmospheric component, a gift from the Gods!Regardless of where the H2 comes from, the Sabatier reaction remains the core of future martian mission. NASA understood that because they have developped a methane/O2 rocket already.So the only things you really need to bring to Mars in preparation of a human sejour is....energy.Anything necessary for humans can be me made in situ.Beside the Sabatier, it should be possible to fractionate the martian atmosphere to pressurize an inflatable habitat with Argon and Nitrogen, complemented with oxygen from electrolysis to make it breathable.

Zubrin's MArs direct, with or without embarked hydrogen, might be the cheapest, but as I said above, I think that a dedicated interplanetary vehicle whose only role is to shuttle between Earth Orbit and Mars Orbit, would make it even cheaper.The other advantage of Mars is its atmosphere is easy to use for aerobraking. A tall atmospheric column associated with the weaker gravity well of Mars makes it ideal to use, much safer than Earth and not at all like the suicidal aerobraking of "2010 Space Odyssey" in Jupiter.So ideally, an Earth-Mars 'shuttle' should have a large aerobraking shield to assist the orbital insertion on Mars. But obviously this shuttle still needs propellant to escape from Mars orbit, and to reinsert in Earth orbit again. This might be the description of a Mars semi-direct project, I am not sure.

Regarding the costs, the original question, the amounts look like peanuts...compared to the money spend, and lost, during the bank bayloout of 2008.At some point during the hearings, the financial 'experts' forgot if the amount of a particular loan was 49 or 50 billions dollars. Certainly it was rounded at 50 billions, but who knows, not the financial experts anyways. And then 'they' talked about loaning trillions (1 thousand billion), refusing to say to whom, how much and when. I have great doubts that 100% accuracy on such amount was respected. A small 1% error on a 1.4 trillion loan, (such as the one discussed at the 'bernanke grilling' famous all over internet) is still 14 billion dollars....That would pay for a couple of missions. So I don't understand the point of being super picky and talk cut costs (and projects) to save a couple of millions, even one billion, even 10 billions. Earlyer as a sad joke, because unfortunately it was real, i posted about 'high frequency trading' practices that can just 'generate' that amount of money in a few days, using a few kilowatts of electricity to run the computers. Why are we talking to go to Mars on the cheap?

Still in the same wikipedia article on Mars direct, the slightly different scenario of 'semi direct', very similar to the alternative I mentioned above, is evaluated at 55 billions for 10 years.
"...Mars Semi-Direct was predicted to cost 55 billion dollars over 10 years, capable of fitting into the existing NASA budget..."

Even if you ignore what i said about the disconnection between the 'manufacturing world' and the 'financial world', 5 billions a year? that's still peanuts, less than the cost of the F22 raptor program: 66.7 billionshttp://en.wikipedia....wiki/F22_Raptor
Retrospectively, what was the point to cancel 'Constellation', save one or two billions ? I don't get it.

I'm a latte-sipping tree hugger, but you gotta admit there's really nothing like nuclear reactions when it comes to energy. There was a series of totally awesome nuclear propulsion programs a few decades ago, that got cancelled for a variety of reasons, with politics taking a large percentage out of that mix.

NERVA was a fantastic work of science and engineering that showed very promising results. It, too, got killed at a high level. They should make a movie out of it.

Nuclear propulsion is fine in principle, but in practice it can only be used beyond low earth orbit. Problem is, to develop the technology, one must test it on Earth.

I worked for many years just a few miles away from the old Nuclear Rocket test stand and the Engine Maintenance and Assembly/Disassembly facility, or EMAD, on the Nevada test site. Despite the best 1960's efforts, the area was far from clean from a radiological standpoint.